Hannover 2003 – wissenschaftliches Programm
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Q: Quantenoptik
Q 7: Quanteninformation 2
Q 7.1: Vortrag
Montag, 24. März 2003, 14:00–14:15, F102
Compact source of polarization-entangled photon pairs — •Christian Schmid1,2, Pavel Trojek1,2, Mohamed Bourennane1,2, Christian Kurtsiefer1, and Harald Weinfurter1,2 — 1Ludwig-Maximilians-Universität München — 2MPI für Quantenoptik, Garching
Typ II downconversion has established as one of the standard methods for generating entangled photon pairs. However, detection efficiency and dark count noise of currently available single-photon detectors suggest to limit the wavelength range of down-converted photons to 600-900 nm. Consequently, the pump-beam wavelength has to be shorter than 450 nm. Until now, most of the experiments use large frame ion lasers with high operating costs, which are not suitable for practical applications. Hence, it is proximate to think of how to replace these cumbersome and expensive lasers.
We report on development of a compact source of polarization-entangled photon pairs using a blue single-mode laser diode (λ = 402 nm, P = 30 mW) as the pump source of a beta-barium-borate (BBO) nonlinear optical crystal. The created photon pairs are coupled into single-mode optical fibers. The entanglement of the generated photon pairs was tested with the measurement of the polarization correlations in H/V and +45∘/−45∘ basis and by violating the Clauser-Horne-Shimony-Holt (CHSH)-type Bell inequality. This compact, robust and economic source can be employed in any application of quantum cryptography or other quantum communication schemes.